1 files changed, 558 insertions, 0 deletions
diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c
new file mode 100644
index 000000000..7577afd42
--- /dev/null
+++ b/drivers/mfd/intel-lpss.c
@@ -0,0 +1,558 @@
+/*
+ * Intel Sunrisepoint LPSS core support.
+ *
+ * Copyright (C) 2015, Intel Corporation
+ *
+ * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ *          Mika Westerberg <mika.westerberg@linux.intel.com>
+ *          Heikki Krogerus <heikki.krogerus@linux.intel.com>
+ *          Jarkko Nikula <jarkko.nikula@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/debugfs.h>
+#include <linux/idr.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/core.h>
+#include <linux/pm_qos.h>
+#include <linux/pm_runtime.h>
+#include <linux/property.h>
+#include <linux/seq_file.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+
+#include "intel-lpss.h"
+
+#define LPSS_DEV_OFFSET		0x000
+#define LPSS_DEV_SIZE		0x200
+#define LPSS_PRIV_OFFSET	0x200
+#define LPSS_PRIV_SIZE		0x100
+#define LPSS_PRIV_REG_COUNT	(LPSS_PRIV_SIZE / 4)
+#define LPSS_IDMA64_OFFSET	0x800
+#define LPSS_IDMA64_SIZE	0x800
+
+/* Offsets from lpss->priv */
+#define LPSS_PRIV_RESETS		0x04
+#define LPSS_PRIV_RESETS_IDMA		BIT(2)
+#define LPSS_PRIV_RESETS_FUNC		0x3
+
+#define LPSS_PRIV_ACTIVELTR		0x10
+#define LPSS_PRIV_IDLELTR		0x14
+
+#define LPSS_PRIV_LTR_REQ		BIT(15)
+#define LPSS_PRIV_LTR_SCALE_MASK	0xc00
+#define LPSS_PRIV_LTR_SCALE_1US		0x800
+#define LPSS_PRIV_LTR_SCALE_32US	0xc00
+#define LPSS_PRIV_LTR_VALUE_MASK	0x3ff
+
+#define LPSS_PRIV_SSP_REG		0x20
+#define LPSS_PRIV_SSP_REG_DIS_DMA_FIN	BIT(0)
+
+#define LPSS_PRIV_REMAP_ADDR		0x40
+
+#define LPSS_PRIV_CAPS			0xfc
+#define LPSS_PRIV_CAPS_NO_IDMA		BIT(8)
+#define LPSS_PRIV_CAPS_TYPE_SHIFT	4
+#define LPSS_PRIV_CAPS_TYPE_MASK	(0xf << LPSS_PRIV_CAPS_TYPE_SHIFT)
+
+/* This matches the type field in CAPS register */
+enum intel_lpss_dev_type {
+	LPSS_DEV_I2C = 0,
+	LPSS_DEV_UART,
+	LPSS_DEV_SPI,
+};
+
+struct intel_lpss {
+	const struct intel_lpss_platform_info *info;
+	enum intel_lpss_dev_type type;
+	struct clk *clk;
+	struct clk_lookup *clock;
+	struct mfd_cell *cell;
+	struct device *dev;
+	void __iomem *priv;
+	u32 priv_ctx[LPSS_PRIV_REG_COUNT];
+	int devid;
+	u32 caps;
+	u32 active_ltr;
+	u32 idle_ltr;
+	struct dentry *debugfs;
+};
+
+static const struct resource intel_lpss_dev_resources[] = {
+	DEFINE_RES_MEM_NAMED(LPSS_DEV_OFFSET, LPSS_DEV_SIZE, "lpss_dev"),
+	DEFINE_RES_MEM_NAMED(LPSS_PRIV_OFFSET, LPSS_PRIV_SIZE, "lpss_priv"),
+	DEFINE_RES_IRQ(0),
+};
+
+static const struct resource intel_lpss_idma64_resources[] = {
+	DEFINE_RES_MEM(LPSS_IDMA64_OFFSET, LPSS_IDMA64_SIZE),
+	DEFINE_RES_IRQ(0),
+};
+
+#define LPSS_IDMA64_DRIVER_NAME		"idma64"
+
+/*
+ * Cells needs to be ordered so that the iDMA is created first. This is
+ * because we need to be sure the DMA is available when the host controller
+ * driver is probed.
+ */
+static const struct mfd_cell intel_lpss_idma64_cell = {
+	.name = LPSS_IDMA64_DRIVER_NAME,
+	.num_resources = ARRAY_SIZE(intel_lpss_idma64_resources),
+	.resources = intel_lpss_idma64_resources,
+};
+
+static const struct mfd_cell intel_lpss_i2c_cell = {
+	.name = "i2c_designware",
+	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
+	.resources = intel_lpss_dev_resources,
+};
+
+static const struct mfd_cell intel_lpss_uart_cell = {
+	.name = "dw-apb-uart",
+	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
+	.resources = intel_lpss_dev_resources,
+};
+
+static const struct mfd_cell intel_lpss_spi_cell = {
+	.name = "pxa2xx-spi",
+	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
+	.resources = intel_lpss_dev_resources,
+};
+
+static DEFINE_IDA(intel_lpss_devid_ida);
+static struct dentry *intel_lpss_debugfs;
+
+static int intel_lpss_request_dma_module(const char *name)
+{
+	static bool intel_lpss_dma_requested;
+
+	if (intel_lpss_dma_requested)
+		return 0;
+
+	intel_lpss_dma_requested = true;
+	return request_module("%s", name);
+}
+
+static void intel_lpss_cache_ltr(struct intel_lpss *lpss)
+{
+	lpss->active_ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
+	lpss->idle_ltr = readl(lpss->priv + LPSS_PRIV_IDLELTR);
+}
+
+static int intel_lpss_debugfs_add(struct intel_lpss *lpss)
+{
+	struct dentry *dir;
+
+	dir = debugfs_create_dir(dev_name(lpss->dev), intel_lpss_debugfs);
+	if (IS_ERR(dir))
+		return PTR_ERR(dir);
+
+	/* Cache the values into lpss structure */
+	intel_lpss_cache_ltr(lpss);
+
+	debugfs_create_x32("capabilities", S_IRUGO, dir, &lpss->caps);
+	debugfs_create_x32("active_ltr", S_IRUGO, dir, &lpss->active_ltr);
+	debugfs_create_x32("idle_ltr", S_IRUGO, dir, &lpss->idle_ltr);
+
+	lpss->debugfs = dir;
+	return 0;
+}
+
+static void intel_lpss_debugfs_remove(struct intel_lpss *lpss)
+{
+	debugfs_remove_recursive(lpss->debugfs);
+}
+
+static void intel_lpss_ltr_set(struct device *dev, s32 val)
+{
+	struct intel_lpss *lpss = dev_get_drvdata(dev);
+	u32 ltr;
+
+	/*
+	 * Program latency tolerance (LTR) accordingly what has been asked
+	 * by the PM QoS layer or disable it in case we were passed
+	 * negative value or PM_QOS_LATENCY_ANY.
+	 */
+	ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
+
+	if (val == PM_QOS_LATENCY_ANY || val < 0) {
+		ltr &= ~LPSS_PRIV_LTR_REQ;
+	} else {
+		ltr |= LPSS_PRIV_LTR_REQ;
+		ltr &= ~LPSS_PRIV_LTR_SCALE_MASK;
+		ltr &= ~LPSS_PRIV_LTR_VALUE_MASK;
+
+		if (val > LPSS_PRIV_LTR_VALUE_MASK)
+			ltr |= LPSS_PRIV_LTR_SCALE_32US | val >> 5;
+		else
+			ltr |= LPSS_PRIV_LTR_SCALE_1US | val;
+	}
+
+	if (ltr == lpss->active_ltr)
+		return;
+
+	writel(ltr, lpss->priv + LPSS_PRIV_ACTIVELTR);
+	writel(ltr, lpss->priv + LPSS_PRIV_IDLELTR);
+
+	/* Cache the values into lpss structure */
+	intel_lpss_cache_ltr(lpss);
+}
+
+static void intel_lpss_ltr_expose(struct intel_lpss *lpss)
+{
+	lpss->dev->power.set_latency_tolerance = intel_lpss_ltr_set;
+	dev_pm_qos_expose_latency_tolerance(lpss->dev);
+}
+
+static void intel_lpss_ltr_hide(struct intel_lpss *lpss)
+{
+	dev_pm_qos_hide_latency_tolerance(lpss->dev);
+	lpss->dev->power.set_latency_tolerance = NULL;
+}
+
+static int intel_lpss_assign_devs(struct intel_lpss *lpss)
+{
+	const struct mfd_cell *cell;
+	unsigned int type;
+
+	type = lpss->caps & LPSS_PRIV_CAPS_TYPE_MASK;
+	type >>= LPSS_PRIV_CAPS_TYPE_SHIFT;
+
+	switch (type) {
+	case LPSS_DEV_I2C:
+		cell = &intel_lpss_i2c_cell;
+		break;
+	case LPSS_DEV_UART:
+		cell = &intel_lpss_uart_cell;
+		break;
+	case LPSS_DEV_SPI:
+		cell = &intel_lpss_spi_cell;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	lpss->cell = devm_kmemdup(lpss->dev, cell, sizeof(*cell), GFP_KERNEL);
+	if (!lpss->cell)
+		return -ENOMEM;
+
+	lpss->type = type;
+
+	return 0;
+}
+
+static bool intel_lpss_has_idma(const struct intel_lpss *lpss)
+{
+	return (lpss->caps & LPSS_PRIV_CAPS_NO_IDMA) == 0;
+}
+
+static void intel_lpss_set_remap_addr(const struct intel_lpss *lpss)
+{
+	resource_size_t addr = lpss->info->mem->start;
+
+	lo_hi_writeq(addr, lpss->priv + LPSS_PRIV_REMAP_ADDR);
+}
+
+static void intel_lpss_deassert_reset(const struct intel_lpss *lpss)
+{
+	u32 value = LPSS_PRIV_RESETS_FUNC | LPSS_PRIV_RESETS_IDMA;
+
+	/* Bring out the device from reset */
+	writel(value, lpss->priv + LPSS_PRIV_RESETS);
+}
+
+static void intel_lpss_init_dev(const struct intel_lpss *lpss)
+{
+	u32 value = LPSS_PRIV_SSP_REG_DIS_DMA_FIN;
+
+	/* Set the device in reset state */
+	writel(0, lpss->priv + LPSS_PRIV_RESETS);
+
+	intel_lpss_deassert_reset(lpss);
+
+	intel_lpss_set_remap_addr(lpss);
+
+	if (!intel_lpss_has_idma(lpss))
+		return;
+
+	/* Make sure that SPI multiblock DMA transfers are re-enabled */
+	if (lpss->type == LPSS_DEV_SPI)
+		writel(value, lpss->priv + LPSS_PRIV_SSP_REG);
+}
+
+static void intel_lpss_unregister_clock_tree(struct clk *clk)
+{
+	struct clk *parent;
+
+	while (clk) {
+		parent = clk_get_parent(clk);
+		clk_unregister(clk);
+		clk = parent;
+	}
+}
+
+static int intel_lpss_register_clock_divider(struct intel_lpss *lpss,
+					     const char *devname,
+					     struct clk **clk)
+{
+	char name[32];
+	struct clk *tmp = *clk;
+
+	snprintf(name, sizeof(name), "%s-enable", devname);
+	tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0,
+				lpss->priv, 0, 0, NULL);
+	if (IS_ERR(tmp))
+		return PTR_ERR(tmp);
+
+	snprintf(name, sizeof(name), "%s-div", devname);
+	tmp = clk_register_fractional_divider(NULL, name, __clk_get_name(tmp),
+					      0, lpss->priv, 1, 15, 16, 15, 0,
+					      NULL);
+	if (IS_ERR(tmp))
+		return PTR_ERR(tmp);
+	*clk = tmp;
+
+	snprintf(name, sizeof(name), "%s-update", devname);
+	tmp = clk_register_gate(NULL, name, __clk_get_name(tmp),
+				CLK_SET_RATE_PARENT, lpss->priv, 31, 0, NULL);
+	if (IS_ERR(tmp))
+		return PTR_ERR(tmp);
+	*clk = tmp;
+
+	return 0;
+}
+
+static int intel_lpss_register_clock(struct intel_lpss *lpss)
+{
+	const struct mfd_cell *cell = lpss->cell;
+	struct clk *clk;
+	char devname[24];
+	int ret;
+
+	if (!lpss->info->clk_rate)
+		return 0;
+
+	/* Root clock */
+	clk = clk_register_fixed_rate(NULL, dev_name(lpss->dev), NULL, 0,
+				      lpss->info->clk_rate);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	snprintf(devname, sizeof(devname), "%s.%d", cell->name, lpss->devid);
+
+	/*
+	 * Support for clock divider only if it has some preset value.
+	 * Otherwise we assume that the divider is not used.
+	 */
+	if (lpss->type != LPSS_DEV_I2C) {
+		ret = intel_lpss_register_clock_divider(lpss, devname, &clk);
+		if (ret)
+			goto err_clk_register;
+	}
+
+	ret = -ENOMEM;
+
+	/* Clock for the host controller */
+	lpss->clock = clkdev_create(clk, lpss->info->clk_con_id, "%s", devname);
+	if (!lpss->clock)
+		goto err_clk_register;
+
+	lpss->clk = clk;
+
+	return 0;
+
+err_clk_register:
+	intel_lpss_unregister_clock_tree(clk);
+
+	return ret;
+}
+
+static void intel_lpss_unregister_clock(struct intel_lpss *lpss)
+{
+	if (IS_ERR_OR_NULL(lpss->clk))
+		return;
+
+	clkdev_drop(lpss->clock);
+	intel_lpss_unregister_clock_tree(lpss->clk);
+}
+
+int intel_lpss_probe(struct device *dev,
+		     const struct intel_lpss_platform_info *info)
+{
+	struct intel_lpss *lpss;
+	int ret;
+
+	if (!info || !info->mem || info->irq <= 0)
+		return -EINVAL;
+
+	lpss = devm_kzalloc(dev, sizeof(*lpss), GFP_KERNEL);
+	if (!lpss)
+		return -ENOMEM;
+
+	lpss->priv = devm_ioremap_uc(dev, info->mem->start + LPSS_PRIV_OFFSET,
+				  LPSS_PRIV_SIZE);
+	if (!lpss->priv)
+		return -ENOMEM;
+
+	lpss->info = info;
+	lpss->dev = dev;
+	lpss->caps = readl(lpss->priv + LPSS_PRIV_CAPS);
+
+	dev_set_drvdata(dev, lpss);
+
+	ret = intel_lpss_assign_devs(lpss);
+	if (ret)
+		return ret;
+
+	lpss->cell->properties = info->properties;
+
+	intel_lpss_init_dev(lpss);
+
+	lpss->devid = ida_simple_get(&intel_lpss_devid_ida, 0, 0, GFP_KERNEL);
+	if (lpss->devid < 0)
+		return lpss->devid;
+
+	ret = intel_lpss_register_clock(lpss);
+	if (ret)
+		goto err_clk_register;
+
+	intel_lpss_ltr_expose(lpss);
+
+	ret = intel_lpss_debugfs_add(lpss);
+	if (ret)
+		dev_warn(dev, "Failed to create debugfs entries\n");
+
+	if (intel_lpss_has_idma(lpss)) {
+		/*
+		 * Ensure the DMA driver is loaded before the host
+		 * controller device appears, so that the host controller
+		 * driver can request its DMA channels as early as
+		 * possible.
+		 *
+		 * If the DMA module is not there that's OK as well.
+		 */
+		intel_lpss_request_dma_module(LPSS_IDMA64_DRIVER_NAME);
+
+		ret = mfd_add_devices(dev, lpss->devid, &intel_lpss_idma64_cell,
+				      1, info->mem, info->irq, NULL);
+		if (ret)
+			dev_warn(dev, "Failed to add %s, fallback to PIO\n",
+				 LPSS_IDMA64_DRIVER_NAME);
+	}
+
+	ret = mfd_add_devices(dev, lpss->devid, lpss->cell,
+			      1, info->mem, info->irq, NULL);
+	if (ret)
+		goto err_remove_ltr;
+
+	dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND);
+
+	return 0;
+
+err_remove_ltr:
+	intel_lpss_debugfs_remove(lpss);
+	intel_lpss_ltr_hide(lpss);
+	intel_lpss_unregister_clock(lpss);
+
+err_clk_register:
+	ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(intel_lpss_probe);
+
+void intel_lpss_remove(struct device *dev)
+{
+	struct intel_lpss *lpss = dev_get_drvdata(dev);
+
+	mfd_remove_devices(dev);
+	intel_lpss_debugfs_remove(lpss);
+	intel_lpss_ltr_hide(lpss);
+	intel_lpss_unregister_clock(lpss);
+	ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
+}
+EXPORT_SYMBOL_GPL(intel_lpss_remove);
+
+static int resume_lpss_device(struct device *dev, void *data)
+{
+	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND))
+		pm_runtime_resume(dev);
+
+	return 0;
+}
+
+int intel_lpss_prepare(struct device *dev)
+{
+	/*
+	 * Resume both child devices before entering system sleep. This
+	 * ensures that they are in proper state before they get suspended.
+	 */
+	device_for_each_child_reverse(dev, NULL, resume_lpss_device);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_lpss_prepare);
+
+int intel_lpss_suspend(struct device *dev)
+{
+	struct intel_lpss *lpss = dev_get_drvdata(dev);
+	unsigned int i;
+
+	/* Save device context */
+	for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
+		lpss->priv_ctx[i] = readl(lpss->priv + i * 4);
+
+	/*
+	 * If the device type is not UART, then put the controller into
+	 * reset. UART cannot be put into reset since S3/S0ix fail when
+	 * no_console_suspend flag is enabled.
+	 */
+	if (lpss->type != LPSS_DEV_UART)
+		writel(0, lpss->priv + LPSS_PRIV_RESETS);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_lpss_suspend);
+
+int intel_lpss_resume(struct device *dev)
+{
+	struct intel_lpss *lpss = dev_get_drvdata(dev);
+	unsigned int i;
+
+	intel_lpss_deassert_reset(lpss);
+
+	/* Restore device context */
+	for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
+		writel(lpss->priv_ctx[i], lpss->priv + i * 4);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_lpss_resume);
+
+static int __init intel_lpss_init(void)
+{
+	intel_lpss_debugfs = debugfs_create_dir("intel_lpss", NULL);
+	return 0;
+}
+module_init(intel_lpss_init);
+
+static void __exit intel_lpss_exit(void)
+{
+	ida_destroy(&intel_lpss_devid_ida);
+	debugfs_remove(intel_lpss_debugfs);
+}
+module_exit(intel_lpss_exit);
+
+MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
+MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
+MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
+MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>");
+MODULE_DESCRIPTION("Intel LPSS core driver");
+MODULE_LICENSE("GPL v2");